Ski



Aug. 29, 1944.

- A. D. ANDREEF SKIS AFiled April 22, 1942,

2 Sheets-'Sheet 1 lNvENv'roR -ApqxnDReEF A'rron s Aug. 29, 1944.

A. D. ANDREEF SKIS 2 Sheets-Sheet 2` Filed April 22; 1942 n m p" n mn wm ov Patented-i Aug. 2g, 1944 FHCE SKI 7 Claims.

Two-layer skis hage been made with a thin, I.

y full length bottom layer `of uniform thickness from end to end and a relatively thick, full length top layer which is tapered so that its end portions are relatively thin and iiexible compared with its middle portion. 'Such skis are weakened during the process oi manufacture by reason of the fact that the thickness and bending resistance of the top layer requires the application ofA a heavy molding or bending pressure to give the laminated ski the required longitudinal curvature and camber. This heavy pressure, in overcoming the bending resistance of the relatively thick top layer, causes the wood libres of said layer 'to be crushed and otherwise damaged so that this layerY loses xmuch of its original strength and flexibility during the bending operations. Another objection to the two-layer ski mentioned herein'is that, owing to the great disparity between the thickness of the bottom layer and the thickness of the top layer, the bottomlayer is too weak to prevent warpage of the ski due to the internal working and twisting tendency of the relatively stronger top layer.

Three-layer skis have been made with a tapered central layer or core locked in place.between rellare directly joined together beyond the corresponding ends of the Acentral nrcore layer which istapered so that it decreases in thickness from its middle toward its end portions. This type of three-layer ski is subjectto breakage at or ad- ',iacent the thin ends of the' central or core layer.

It is also open to the objection that the two,`

, layer end portions thereof do not long retain their original curvature and are easily warped.

According to the present invention all the fore- *v going objections are eliminated bythe improved -multi-layerski constructions which will now be described with reference to drawings, in which- Figure 1 is a side'elevation of a two-layer ski embodying my invention. Figure 2 is a side elevation of a three-laye ski.

Figure 3ds a side elevation of a -four-layer the accompanying Figure 4 is an enlarged transverse sectional view taken substantially along thel line d-li of Fig. 3.

Figure 5 is a view similar to Fig. 4 but showing a modied type of four-layerski.

Figure 6 is a view similar to Figs. 4 and showing alfive-layer ski.

Figure 7 is a side elevation of a six-layer ski.v Figure 8 is a side elevation of a modified form of six-layer ski. i

Figure 9 is a side elevation showing a further type of four-layer ski.

Figure 10 is an. enlarged transverse sectional view taken substantially along the line illi0 of Fig. 9.

Figure 11 is an enlarged transverse sectional view taken substantially along the line H-H of Fig. 9.

The two-layerski shown in Fig. 1 `comprises full length taperedlayers 5 and 6 of duplicate construction. These layers are preformed so that they gradually decrease in thickness from the middle `toward theend portions thereof.

They are, insofar as it is practicable to makethem so with present manufacturing methods,

exact duplicates -as regards length, width and thickness. Asregards the thickness characterof the top layer 5 at any given point along the "entire length of the ski shall be the same as the thickness of the bottom layer 6 at the same point. This equalization of the thickness of the two layers at all corresponding Vpoints along the length of the ski produces an improved laminated are made of wood-of equal strength character' construction in which the strength and thickl ness and, consequently, the magnitude of the internal workingand twisting tendency of one layer at any given point along the length of the ski is exactly counterbalanced by the strength, thickness and magnitude of the internal working and twisting tendency. of the companion layer at the same point in all cases in which the two laye/rs l5 but istics.v This permits the two layers.to be as-` ysembled so that, in the-iinished ski, the internal working and twisting tendency of one layer which Y tends to cause warpaze isropposed and neutralized by the internal working'and twisting tendency of the vcompanion layer at all points along the length of the ski. It is not .necessary that the two layers be made of wood having exactly the same weight characteristics but it is important that the wood used in.both layers should be uniform as regards strength and internal working or warping characteristics.

The ends of the nished ski shown in Fig. 1 are thickened and strengthened by toe and heel shaping wedges 1 and 8 interposed between the layers 5 and 6. These wedges are formed and fitted in place so that the grain thereof is at right angles tothe grain of the layers 5 and 6. It may be noted here that all the component parts of the ski, comprising the layers 5 and 6 and the shaping wedges 1 and 8 are firmly joined together by conventional gluing and pressing operations. The layers 5 and B may be of one piece construction or, alternately, either or both of them may be composed of narrow lengthwise extending strips or rails glued together in side by side relation. M

Another advantage-of the ski shown in Fig. 1

is that its swing retaining characteristics areA substantially improved by reason of the fact that both layers have practically the same longitudinal curvature and are of equal thickness at all corresponding points along the length thereof. In skis where there is substantial variation in the length and curvature of component layers or in the thickness of such layers at corresponding points along the length of the ski, the swing characteristics of the ski, as a whole, is impaired by the lack of uniformity of the swing retaining characteristics of the component layers as-compared with each other. It is also true that the best results, as regards warpage resistance and swing retaining characteristics, are not obtained in multi-layer skis in which there is considerable disparity between. thevstrength and. thickness of corresponding portions of the layers forming the thinner or end portions of the complete ski.

A further advantage to be noted in connection with the ski shown in Fig. l is that the top and bottom layers are substantially thinner than the single tapered top layer of the previously mentioned conventional two-layer ski and may, therefore, be bent to the required longitudinal curvature or camber by the application of considerably less bending. pressure vand with less damage to the fibres of the wood.

In Fig. 2I have shown a modified form of ski composed of three full length layers including a top layer III. an intermediate layer II and a. bottom or runner layer I2. The layersl I and II are made in exactly the same way as the previously mentioned layers and 6, ex-

'and the thickness of the thicker portions of the superimposed taper shaping layersili and II is of no consequence since the layers I0 and II provide a non-warping body portion which is 'effective to prevent any warping of the weaker runner layer I2. The swing retaining and warp.

age resistance characteristics of the three layer the three layer ski shown in Fig. 2 is superior cept that they are made thinner at all corresponding points along their length so that the addition of the third or runner layer I2 produces a three layer ski which has the same overall thickness as the two layer ski shown in Fig. l.

` In this connection it will be understood that the overall thickness of the three layer Vski shown.

in Fig.' 2 has been exaggerated to permit a clearer showing of the component layers. 'I'he bottom or runner layer I2 shown in Fig. 2 is preferably of uniform thickness from end to end and is irelatively thin compared to the thicker portions the associated layers III and I I, the thickness o the layer I2 being preferably the same as thauof the thinnest portions of the tapered layers III and II. In this case the disparity between thethickness of the bottom or runner layer I2 tapered layers employed are thinner than those employed in the two layer ski and therefore may be bent to the required longitudinal curvature.y

or camber with less pressure and with less danger of damaging the wood fibres. It may also be noted here that the division of the total thickness of the ski between three layers instead of between two layers provides a generally stronger construction which is more resistant to warpage. It may also be pointed out here that, in a 'ski composed of three full length layers, the thinner or end portions of the ski tend to retain their original curvature to a much greater extent as compared with the end portions of skis made only of two superimposed layers. v

Each of the component layers of the ski shown in Fig. 2 may be of one piece construction, or alternatively, may be composed of narrow longitudinally extending strips or rails glued together in side by side relation; In this connection it will be understood that one or more layers may be of one piece construction and the remaining layer or layers made of narrow strips or rails glued together in side by side relation.

In Figs. 3 and 4 I have shown a four layer ski comprising two full length tapered layers I5 and I6 `of duplicate construction and two full length non-tapered layers I1 and I8. In this case the layers I5 and I64 are tapered in the same manner `as described in connection with the tapered layers of Figs. 1 and 2 but are separated from each other by the interposition of the non-tapered layer I1. The layers I1 and I8 are of uniform thickness from end to end and are substantially thinner than the thicker portions of the tapered layers I5 and I 6. The layers I1 and I8 are also preferably of equal thickness as compared with each other.

Another `important feature of the four layer ski shown in Figs. 3 and 4 is that each of the.

4 In this connection, it is particularly important that, in the thinnerportions of the skis, solid or one piece layers be interposed between and secured to those layers which are composed of rails glued together in side by side relation. This arrangement of the layers is resistant to vboth transverse and longitudinal curvature or warpage.

In Fig. 5 I have shown a further example of a four layer ski embodying the principles of my invention. In this case the top and bottom layers 20 and 2| are of uniform thickness from end to end and are relatively thin compared with the thicker portions of the duplicate intermediate layers 22 and 23`which are tapered so that they gradually decrease in thickness from the middle toward the end portions thereof.` Each ofthe top and bottom layers 20 and 2| is of one piece construction while the intermediate layers 22 and 23 are each composed of a plurality of narrow strips or rails glued together in side by side relation.

In Fig. 6 I have shown a ve layer ski in which the top layer 25, the central layer 26 and the bottom. or runner layer 21 are of uniform thickness from end to end and are relatively thin compared with the thicker portions of the remaining layers 281 and 29- which are tapered so that they decrease in thickness from the middle toward the end portions thereof. In this case the tapered layers 23 and 23 are of duplicate construction and are each composed of a series of narrow strips or rails glued together in side by side relation, the upper tapered layer 28 being sandwiched between the top layer 25 and the central layer 26 and the lower tapered layer 23 being sandwiched between the central layer 2E and the bottom or runner layer 2.

In connection with the skis shown` in Figs. and 6 it will be understood that' all the com, ponent layers extend the full length of the ski so that the end portions of the ski will have the same number of laminatons or layers as the central portion.

In Fig. 7 I have shown a six layer ski which comprisesve full length tapered layers 3U, 3l,

32. 33 and 34 of duplicate construction and a single full length bottom layer 35 which is of uniform thickness from end to 4end and is relatively thin compared with the thicker portions of the tapered layers.

In Fig. 8 I have shown a further type of six layer ski which comprises three full length tapered layers 31, 38 and 39 of duplicate construction and three full length non-tapered layers 40, 4I and 42. The three last mentioned layers are of uniform thickness from end to end and are relatively thin compared to the thicker portions of the taperedlayers. tapered and non-tapered layers are alternately 'arranged so that the tapered layer 31 forms the top layer while the non-tapered layer 42 forms the bottom or runner layer, the nontapered layer 40 being interposed between the two tapered layers 3l and 38 and the nontapered layer 4| being interposed between the tapered'layers `38 and 39. In the case of the six layer ski shown in Fig. 8 an exceedingly good construction is obtained by forming each tapered layer so that it consists of narrow strips or rails glued together in side by side relation, the remaining or non-tapered layers being of one piece construction. However, it will be understood that, with reference to all of the diierent types of skis described herein, certain component layers may be of one piece construction and the remaining layer or layers composed of narrow strips or rails glued together in side by side relation. In all cases, however, it is essential that the tapered layers be of equal thickness at all corresponding points along the length thereof.

In Figs. 9 to ll inclusive I have shown a further In this case the type of ski comprising four superimposed layers designated 4.4, 45, 46 and 41. The two upper layers 44 and 45 are tapered so that they gradually decrease inthicknessfrom the middle toward the end portions thereof, these layers being of equal thickness at corresponding points alongV the ski the thickness of the layer 46 is somewhat greater than the thickness of each of the layers 44, 45 and 41 at the same portions ofthe ski. This provides a very desirable type of ski in which the layers 44 and 43, being composed of rails glued together in side by side relation, have little tendency to warp and serve to prevent warping of the layers 45 and 41 at the end or thin portions of the ski where warpage is most likely to occur. The layers 45 and 4l, being of solid construction, tend to support the layers 44 and 4S against the rolling or curving action which is characteristic of skis in which certain layers are composed of rails glued together in side by side relation. Y f i Having thus described. my invention, what I claim is:

1. A laminated ski including a plurality of superimposed full length tapered layers forming the main or body portion of the ski and one or more full length runner layers secured -to the bottom surface of the .lowermost of the body forming layers; said runner layer or layers being of uniform thickness from end to end and being relatively thin compared with the thicker portions of the tapered body forming layers, said ski being further characterised in that the body forming layers are of equal thickness at any given point along the length of the ski.

2. A- three layer laminated ski in which all the layers .extend the full length of the ski, thetop and intermediate layers being tapered so that they gradually decrease in thickness from the middle toward the end portions thereof and the bottom or runner layer being of uniform thickness from end to end and being relatively thin compared with the thicker portions of the tapered layers, said ski being further characterized in that the thickness of each tapered layer, as measured at any given'point along thelength of the ski, is substantiallyexactly equal' to the thickness of the companion tapered layer as meas-'- ured at the same point along thelength of the ski.

3. A four layer laminated ski comprising two full length tapered layers alternately arranged with respect .to two full length'non-tapered layers, said tapered layers being of gradually decreasing thickness from the middle toward the end portions thereof and being formed so that the thickness of each tapered layer, as measured at any given point along the length of the ski, is

substantially equal to the thickness of the com-- panion tapered layer as measured at the same point along the length of the ski, 'each of said non-taperedvlayers beingof uniform thickness from endto end and being relatively thin compared with the thicker portions of the tapered layers.

4. A four layer ski as set' forth in claim 3 in which the .tapered and non-tapered layers are alternately arranged so that one of thetapered layers constitutes the top layer` of the ski While one of the non-tapered layers constitutes the bottom layer of the ski. Y

point along the length of the ski, each of said' tapered layers consisting of a plurality of narrow strips or rails glued together in side by side relai tion and each of said non-tapered layers being of one piece construction and ofa thickness which is substantially less than the thickness of the middle portions of the tapered layers.

6. A multiple layer ski in which all of the layers extend the full length of the ski, two of said layers being taperedso that they decrease in thickness from the middle toward the end portions thereof, said tapered layers being also formed so that the thickness of one, as measured at any given point along'vthe length of the ski, is substantially exactly equal to .the thickness of the other as measured at the same point along the length of the ski, the non-tapered layers being of substantially uniform thickness from end to end.

'1. A multiple layer ski as set forth in claim 6 in which each non-tapered layer is ottone piece construction and in which each tapered layer is composed of narrow lengthwise extending strips or rails glued together in side by side relation and is sandwiched in place between two of the nontapered layers.

ALEXIS D. ANDREEF. 

